[Xen-devel] [PATCH V3 1/2] x86/altp2m: Add hypercall to set a range of sve bits

[Alexandru Stefan ISAILA <aisaila@xxxxxxxxxxxxxxx>]

By default the sve bits are not set.
This patch adds a new hypercall, xc_altp2m_set_supress_ve_multi(),
to set a range of sve bits.
The core function, p2m_set_suppress_ve_multi(), does not brake in case
of a error and it is doing a best effort for setting the bits in the
given range. A check for continuation is made in order to have
preemption on big ranges.

Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>
---
CC: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
CC: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
CC: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
CC: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
CC: Petre Pircalabu <ppircalabu@xxxxxxxxxxxxxxx>
---
Changes since V2:
        - Add a new structure "xen_hvm_altp2m_suppress_ve_multi"
        - Copy the gfn of the first error to the caller
        - Revert xen_hvm_altp2m_suppress_ve
        - Add a mechanism to save the first error.
---
 tools/libxc/include/xenctrl.h   |  4 +++
 tools/libxc/xc_altp2m.c         | 30 +++++++++++++++++
 xen/arch/x86/hvm/hvm.c          | 13 +++++++
 xen/arch/x86/mm/p2m.c           | 60 +++++++++++++++++++++++++++++++++
 xen/include/public/hvm/hvm_op.h | 14 ++++++++
 xen/include/xen/mem_access.h    |  3 ++
 6 files changed, 124 insertions(+)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index f4431687b3..356533e391 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1923,6 +1923,10 @@ int xc_altp2m_switch_to_view(xc_interface *handle, 
uint32_t domid,
                              uint16_t view_id);
 int xc_altp2m_set_suppress_ve(xc_interface *handle, uint32_t domid,
                               uint16_t view_id, xen_pfn_t gfn, bool sve);
+int xc_altp2m_set_supress_ve_multi(xc_interface *handle, uint32_t domid,
+                                   uint16_t view_id, xen_pfn_t first_gfn,
+                                   xen_pfn_t last_gfn, bool sve,
+                                   xen_pfn_t *error);
 int xc_altp2m_get_suppress_ve(xc_interface *handle, uint32_t domid,
                               uint16_t view_id, xen_pfn_t gfn, bool *sve);
 int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index 09dad0355e..03bd651a61 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -234,6 +234,36 @@ int xc_altp2m_set_suppress_ve(xc_interface *handle, 
uint32_t domid,
     return rc;
 }
 
+int xc_altp2m_set_supress_ve_multi(xc_interface *handle, uint32_t domid,
+                                   uint16_t view_id, xen_pfn_t first_gfn,
+                                   xen_pfn_t last_gfn, bool sve,
+                                   xen_pfn_t *error)
+{
+    int rc;
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
+
+    arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
+    arg->cmd = HVMOP_altp2m_set_suppress_ve_multi;
+    arg->domain = domid;
+    arg->u.suppress_ve_multi.view = view_id;
+    arg->u.suppress_ve_multi.first_gfn = first_gfn;
+    arg->u.suppress_ve_multi.last_gfn = last_gfn;
+    arg->u.suppress_ve_multi.suppress_ve = sve;
+
+    rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
+                  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    if ( arg->u.suppress_ve_multi.first_error )
+        *error = arg->u.suppress_ve_multi.first_error;
+
+    xc_hypercall_buffer_free(handle, arg);
+    return rc;
+}
+
 int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
                              uint16_t view_id, xen_pfn_t gfn,
                              xenmem_access_t access)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 818e705fd1..8a2d4325f9 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4553,6 +4553,7 @@ static int do_altp2m_op(
     case HVMOP_altp2m_destroy_p2m:
     case HVMOP_altp2m_switch_p2m:
     case HVMOP_altp2m_set_suppress_ve:
+    case HVMOP_altp2m_set_suppress_ve_multi:
     case HVMOP_altp2m_get_suppress_ve:
     case HVMOP_altp2m_set_mem_access:
     case HVMOP_altp2m_set_mem_access_multi:
@@ -4711,6 +4712,18 @@ static int do_altp2m_op(
         }
         break;
 
+    case HVMOP_altp2m_set_suppress_ve_multi:
+        if ( a.u.suppress_ve_multi.pad1 || !a.u.suppress_ve_multi.pad2 )
+            rc = -EINVAL;
+        else
+        {
+            rc = p2m_set_suppress_ve_multi(d, &a.u.suppress_ve_multi);
+
+            if ( __copy_to_guest(arg, &a, 1) )
+                rc = -EFAULT;
+        }
+        break;
+
     case HVMOP_altp2m_get_suppress_ve:
         if ( a.u.suppress_ve.pad1 || a.u.suppress_ve.pad2 )
             rc = -EINVAL;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index ba126f790a..2b51a7f50f 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -3059,6 +3059,66 @@ out:
     return rc;
 }
 
+/*
+ * Set/clear the #VE suppress bit for multiple pages.  Only available on VMX.
+ */
+int p2m_set_suppress_ve_multi(struct domain *d,
+                              struct xen_hvm_altp2m_suppress_ve_multi *sve)
+{
+    struct p2m_domain *host_p2m = p2m_get_hostp2m(d);
+    struct p2m_domain *ap2m = NULL;
+    struct p2m_domain *p2m;
+    uint64_t start = sve->opaque ?: sve->first_gfn;
+    int rc = 0;
+
+    if ( sve->view > 0 )
+    {
+        if ( sve->view >= MAX_ALTP2M ||
+             d->arch.altp2m_eptp[sve->view] == mfn_x(INVALID_MFN) )
+            return -EINVAL;
+
+        p2m = ap2m = d->arch.altp2m_p2m[sve->view];
+    }
+    else
+        p2m = host_p2m;
+
+    p2m_lock(host_p2m);
+
+    if ( ap2m )
+        p2m_lock(ap2m);
+
+
+    while ( sve->last_gfn >= start )
+    {
+        p2m_access_t a;
+        p2m_type_t t;
+        mfn_t mfn;
+
+        if ( altp2m_get_effective_entry(p2m, _gfn(start), &mfn, &t, &a, 
AP2MGET_query) )
+            a = p2m->default_access;
+
+        if ( p2m->set_entry(p2m, _gfn(start), mfn, PAGE_ORDER_4K, t, a,
+                            sve->suppress_ve) && !sve->first_error )
+            sve->first_error = start; /* Save the gfn from of the first error 
*/
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( sve->last_gfn >= ++start && hypercall_preempt_check() )
+        {
+            rc = -ERESTART;
+            break;
+        }
+    }
+
+    sve->opaque = start;
+
+    if ( ap2m )
+        p2m_unlock(ap2m);
+
+    p2m_unlock(host_p2m);
+
+    return rc;
+}
+
 int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,
                         unsigned int altp2m_idx)
 {
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 353f8034d9..10ba0149f1 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -46,6 +46,17 @@ struct xen_hvm_altp2m_suppress_ve {
     uint64_t gfn;
 };
 
+struct xen_hvm_altp2m_suppress_ve_multi {
+    uint16_t view;
+    uint8_t suppress_ve; /* Boolean type. */
+    uint8_t pad1;
+    uint32_t pad2;
+    uint64_t first_gfn;
+    uint64_t last_gfn;
+    uint64_t opaque;
+    uint64_t first_error; /* Gfn of the first error. */
+};
+
 #if __XEN_INTERFACE_VERSION__ < 0x00040900
 
 /* Set the logical level of one of a domain's PCI INTx wires. */
@@ -339,6 +350,8 @@ struct xen_hvm_altp2m_op {
 #define HVMOP_altp2m_vcpu_disable_notify  13
 /* Get the active vcpu p2m index */
 #define HVMOP_altp2m_get_p2m_idx          14
+/* Set the "Supress #VE" bit for a range of pages */
+#define HVMOP_altp2m_set_suppress_ve_multi 15
     domid_t domain;
     uint16_t pad1;
     uint32_t pad2;
@@ -353,6 +366,7 @@ struct xen_hvm_altp2m_op {
         struct xen_hvm_altp2m_change_gfn           change_gfn;
         struct xen_hvm_altp2m_set_mem_access_multi set_mem_access_multi;
         struct xen_hvm_altp2m_suppress_ve          suppress_ve;
+        struct xen_hvm_altp2m_suppress_ve_multi    suppress_ve_multi;
         struct xen_hvm_altp2m_vcpu_disable_notify  disable_notify;
         struct xen_hvm_altp2m_get_vcpu_p2m_idx     get_vcpu_p2m_idx;
         uint8_t pad[64];
diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
index e4d24502e0..00e594a0ad 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -75,6 +75,9 @@ long p2m_set_mem_access_multi(struct domain *d,
 int p2m_set_suppress_ve(struct domain *d, gfn_t gfn, bool suppress_ve,
                         unsigned int altp2m_idx);
 
+int p2m_set_suppress_ve_multi(struct domain *d,
+                              struct xen_hvm_altp2m_suppress_ve_multi 
*suppress_ve);
+
 int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,
                         unsigned int altp2m_idx);
 
-- 
2.17.1

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